Vibration suppressor



7 June 17, 1941. J, o, ALMEN 2,246,232

VIBRATION SUPPRES 50R Filed Nov. 4, 1940 3nnentor fu/m (9, Q/zzzez;

' (Ittomegs Patented June 17, 1941 Q fa z iazszfi I h I WIQN ears I w 0. Almen, Royal Oak; Mich.', a'ssignor -to .4 r 4' General Motors corporation,a DetroiL-Mich .a s

,corporatiomofDelaware 1.. 'Ap i'eatitnjnov ifib ri 4, 1949; se ial N .'364,14 I

- 9 Claims; (c1.'74-.574);-.. 1 I

This invention relates to devices for suppressing vibrations occurring in shafts.

' The object is to improvefand simplify vibraf-[f tionj suppressing devices of the type comprising an inertiabody coaxial with a shaft subject to torsional or other vibration and driven 'by said: shaft through "elastic means. adapted t'oloaiisthe body to rotate at the mean speed of the'sh'aft;

and to restore it to mean position'with respect to the'shaft'aftentheelastic means has .fbeen distorted. i

The invention" consists of arelatively nular body in combination witha radially corrugated disk spring, to the peripheral portion of which the annular body is attached, and means for securing the central portion of the Spring firmly to a shaft. VIt includes,more'specifically,

means for attaching the annular body tohthe spring consisting of radial inward projecting lugs engaging within theouter ends'of the grooves upon opposite faces of the disk; also aclarn'pirig means for securing the central portion of 'the' disk rigidly to a shaft comprising a fitting having a serrated face engaging the corrugations around a central hole that is provided in the diSk' said fitting constituting one el'inent of, a clamp; a

companion clamping element havingfcorres'ponding serrations forengagin'g the corrugations on the other face of the disk, and a device forforc ing said clamping" elements toward each otherand fixing the elements 'adjustably in 'the dc sired relations for proper tuning "of the device. It also includes means for affording 'frictional damping between shaft and annular body con sisting of a flange-like member fixed to the shaft near the disk springs and body, the outer zone: of'the flangelike member bearing against the adjacent side of the body, whereby relative'an'gui lar movement between body and flange-like mem;

her will be restrained. It also includes furtherf details of structure as fully set forth in the ensuing description.

In the accompanying drawing,

Fig. lis a sectional view of the invention taken on line l-l of Fig.2;

Fig. 2 is an end elevation viewed from apoint at the left of Fig. 1;

Fig; 3 is a view illustrating the annular 'mass and disk spring in position to be assembled, and

also the axiallyseparated elements of a serrated clamping device for securing the disk spring to the shaft, and I Fig. 4 is a section along the curved line' 4-4 of Fig. 2 appearing as if viewed in the direction indicated by the arrows.

In Fig". lnumeralflindica'tes a shaftsuchas the crankshaft of an automobile engine the front end I l 2. of which ijs reduced in diameter providing a] shoulder II 'A tubular fitting l6 surrounds and is keyed to the reduced front end l2 of the shaft. The rearendlof the fitting abut against the shoulder l'4;" the front end is counterbored at I 8 and enlarged in external diameter around thefjcounterb'oreas at 20. Thus are provided 'an' internal[shoulder22 formed by the counterbore,'

and also "an"externafoppositely facing shoulder, 21': "formed'jbyfthe "front end enlargement 2|. Engaging""the'internal' shoulder his the head 26' .of"a'threaded bolt-28 screwedinto a central 'threaded'bore in the endof theredu'ce'dpart l2 of shaft i0. .Bolt 28 thus holds *the fittin l6 against the shoulder 14. A disk or flangelike membr'shown'as a belt pulley "30 is secured to the "fitting I 6 by any suitable means.) The pulley is shown witha. hub-like tubular sleev'e 32= projecting rearward and snugly surrounding the fitting I 6 to which it"is secured,as by'welding as indicated at 34;with the forward faced the pulley seated against the" external shoulder 24 ofthe-fitting; The front end of said-fitting functions asa circularclamp member having a c'rownbffofward-projecting teeth 36 (Fig. 3) separated by spaces having curved throats for apurposeto'be'explained. v

Numeral 40 indicates an annular relatively heavy inertiabody in the nature 'of a fly-wheel" rim connectedsolely to the shelf ID by means of elements tojbefdescribed. The inertia body 40 isprovide'd on its interior surface with two rows of inward projecting lugs, one row in the'example' illustrated consi'stingof four lugs 42lying substantially in one plane'normal to theaxis near the re'arof the'body'w; andthe other rowo on-- sisting offour lugs lying substantially in a other plane'parallel; with the first near the front of'bo'dy 40. The lugs 42 are spaced-90 from each othen and the lugs 44 are also spaced 90 from each other, but lugs 42 are spaced angularly 45 from lugs '44; the lugs therefore are i sta gered relation as shown clear y in 4. The lugs 42' and 44 maybe integral with theannular body or attached thereto'in'any' suitable manner". v

Numeral indicates a corrugated disk spring the corrugations-radiating from the center'to the rim. The spring has a central hole that is preferably of greater diameter than the head 25 0:

bolt 28 in order to provide for a compact assembly. Fromthe central hole in the spring theicor rugations increase in height and "width to "the rim, since the corrugations are formed on radiating lines and are of progressively larger circumferential extent from the center hole to the outer rim. The spring in its unstressed condition is preferably a wide-angle conoidal member and becomes stressed by pressure tending to flatten it. The corrugations are composed of alternating tapering grooves and ridges correspondingly rounded in-icross section as'sh-own inFigA, The grooves the forward face of thespring are indicated by numeral 52 and those on the rearthe shaft and tends to make the entire disk csward face by numeral 54. When the spring disk is assembled with the heavy annulus .40 theiugs 42 extend into four of the grooves 52 on the'i'orward face and the lugs 44 extend .intoiour of 'annular'm'ass on the pulley may be regulated also the grooves 54 on the rearwardfabe. Thus the.

outer portion of the spring and the annular body are mutually held from moving forward .inan ax- 'by tightening :the adjusting screw 62, thereby stiffening itheispring and increasing its natural .*zfrequency of oscillation and also causing it to ial direction out of the space within the inner circumference of the annulus by lugs .42, from moving in the opposite direction with respectto the annu'lusby lugs #4.. r

'The spring diskv .50 may be assembled with an-' nulus flfbydis'torting it into the 'form o'f-a cone of lesser angle than that 'of the spring whenin equilibrium, then-inserting the spring in position withi'n lthe annulus, relaxing the distorting force and allowing the spring to resume its normal state the lugs '42 and I4 entering the outer ends Iof gtherespec'tive grooves .52 and fi l." IEig. 3 shows the (spring .50 distorted to admit .of its ing inserted'past one series .of lugs iinto theposition illustrated. [An-y convenient .fixturel'such .as a suitable form of arbor .press'm'ayfbe used to distortthe spring so as to permit assemblage with the annulus 40.

A' means reacting betweenl'shaft' and spring .for securing the spring to the shaft and varying .its frequency comprises .theielementsnow .tothedescribed.

.A clamping .element 60 is provided ,for .coopcratin with the opposing companion element on the front end of fixture i6. Element .60 is equipped with a crown of teeth filsimilarto teeth 36 .on;fixture l6. Theteethfil areshapedto fit into .the small ends .of grooves 52 in the front face ofspring 50, and the teeth. onfixture .Hi fit into the small ends of grooves .54 in therear face of said spring. Obviously, the teethpnone clamping elementnare opposite the spaces .between the teethinthe other when intercalated with'the Qinnerflnds .of' the corrugation ,on the spring. Thus, when the clamping elements are forced toward one another so that theteethen ter the corrugations they hold the central portion ofthe spring so that it cannotrotate nor .move longitudinally with respect to the, shaft. .The clamping element .60 may be forced toward its companion element .by .a headed adjusting screw 6 2 the shankof which is passedlthrough the cen-. tral .hole shown in .elementfill ,and 'is :threaded into an axial hole in bolt 28 .as :shown in .l.

The adjusting screw 62 tends to increase the stress .on the spring in proportion asit-is-screwed inward. By this .means the vibration frequency of the spring may be-varied andther-spring .tuned to-the required :frequency. v

The spring by reason of its radial corrugations is cap le f y elding. .aangularly so that .the

inner and .outer portions may .become relatively,

displaced, Qor the spring distorted circumferentiall-y. It, therefore, the shaftpscillates torsionally the annular mass functioning/as .aJlywheeI tends. to maintain a steady rotation while the inner portion of .the spring oscillates with press the .annulus 40 with increased force against the pulley 30. The parts in frictional engagement .:cannot creep relative to one another out of a range to .Which, they are restricted by the spring. "The'torsional vibration suppressing action is due in partto the inertia of the mass 40, when thespringis tuned to the proper frequency, tending to restrain oscillations of the shaft by the opposing oscillations of the body and partly to frictional damping due to the rubbingoflugs 4.2 and ii :on the spring and the rubbing of disk 3ll-onthe rear face of body 40. As the spring is susceptible of distortion by transverse oribeam vibrations as Well as by torsional vibrations it will be apparent thatany vibratory tendency of the shaftto which this device maybe attached will be restrained.

1. 'Means for suppressing vibrations in a shaft comprising an annular-inertia body, a disk spring having; radial corrugations extending from the centralport'ion to theouter circumference, means for-attachingthe annular body to .the outer .portion dfthe'spring, and means for connecting the central portion of the spring rigidly to a shaft.

2. A combination as defined in claim .1 in which the'means for attaching theannular .body to the outer portion .of the spring isa frictional connec.

* tion adapted to 'allowa limited angular slippage between body and spring.

'3. Acombinationlas defined in claim 1 in which the means for attaching the annular body to the disk spring comprises two series of radial lugs projectin'g from the'innersurface of theannularbody toward 'the' axis, alternate .lu s engaging in the ends of .grooves on opposite faces of said spring, respectively.

f4. ,Acombinationas defined inclaim 1 in which the means connecting the central ,portion .of the on oneg'fa'ce adjacentto the center,.a companion element having teeth adapted to enterthe grooves on the other face of the diskspringnear thecenter, .and means to .force the companion element axially toward the fitting.

.5. .In means for suppressing vibrations of a sha'ft;the combination of an annular inertia body, with .a diskspring having radialcorrugations-and a central opening; means for attaching the an milar body to the outer portion of the spring; means for connecting th central portion of the spring rigidly to the shaft, said meanscomprising aitubular:fittingadapted.to.be,keyed to the shaft, said ifitting having at .oneend an annular row of teeth adapted to enter the ,grooves in the disk spring on one face adjacent the central opening; a companion element having a central hole and an annular row of teeth corresponding to those of the fitting and adapted to enter the grooves on the other face of the disk spring near the central opening, and means connecting the companion element to the shaft comprising a headed. bolt inserted in the central hole of the element and screw connected with the shaft.

6. A combination as defined in claim 5 in which the tubular fitting is formed with an internal shoulder adjacent the annular row of teeth, a bolt having a head engaging said shoulder and a threaded shank adapted to be screwed into the end of the shaft for forcing the fitting against a shoulder on the shaft, said bolt having a threaded bore to receive the shank of the bolt that holds the companion clamping element in contact with the disk spring.

7. Means for suppressing vibrations in a shaft comprising an annular inertia body; a disk spring having radial corrugations extending from the central portion to the outer circumference; means for attaching the annular body to the outer portion of the spring; means for connecting the central portion of the spring rigidly with the shaft; .a flange-like member rigid with the shaft and in frictional contact with said inertia body.

8. A combination as defined in claim 7 in which the disk spring is in the form of a wide angle cone, with adjustable means reacting between the shaft and the central part of the spring for forcing said central part toward the plane of said flangelike member, thereby stressing the spring.

9. Means for suppressing vibrations in a shaft comprising a conoidal disk spring having radial corrugations, an annular inertia body attached to the outer portion of the spring; means for securing the central portion of the spring to the shaft including means for varying the frequency of the spring by pressure tending to flatten it.

JOHN O. ALMEN. 

